Method and Related Apparatus for Reconfiguring Size of a Receiving Window in a Communications System

A method for reconfiguring a size of a receiving window of a receiver in a communications system comprising:

• receiving a command for reconfiguring the size of the receiving window;
• reconfiguring the size of the receiving window according to the command;
• removing packets with sequence number outside the receiving window with reconfigured size from a buffer of the receiver and delivering the packets to an upper layer;
• determining whether a sequence number of a next expected packet is smaller than or equal to a difference between an upper edge of the receiving window with reconfigured size and the reconfigured size;
• and
• when the sequence number of the next expected packet is smaller than or equal to the difference between the upper edge of the receiving window with reconfigured size and the reconfigured size, the method further comprises:
• (a) setting the sequence number of the next expected packet to be a lower edge of the receiving window;
• (b) delivering a set of received packets with consecutive sequence numbers from the sequence number of the next expected packet up to a sequence number corresponding to a first not received packet of the receiver to the upper layer from the buffer of the receiver;
• and
• (c) setting the sequence number of the next expected packet to be the sequence number corresponding to the first not received packet;
• the method is characterized by further comprising that the set of received packets in step (b) have not been previously delivered to the upper layer.